chm:
CHM is the proprietary help file format generated by Microsoft HTMLHelp Workshop (hhw.exe). It's HTML based help, so topics are required in HTML and supplemented by the used *.jpg, *.gif or e.g. *.svg files. Some additional files for the table of contents (.HHC)and index (.HHK) must be created. The .HHP file is needed for the Workshop project itself. HTMLHelp (HH) was first shipped with Internet Explorer 4 and Windows 95.